Spring suspension system for vehicles



April 21, 1925.

C. THURSTONE SPRING SUSPENSION SYSTEM FOR VEHICLES Filed Feb. 15,' 1923 2 Sheets-Sheet 1 A ril 21, 1925.

C. THURSTONE SPRING SUSPENSION SYSTEM FOR VEHICLES Filed Feb. 15, 1923 2 Sheets-Sheet 2 w. wmmvmmw using pneumatic tires.

use. A further object is to Patented Apr. 2 1, 1925. I

"UNITED STATES PATENT O FFIC CONRAD THURSTONE, OF PITTSBURGH, PENNSYLVANIA.

SPRING SUSPENSION SYSTEM FOR VEHICLES.

Application filed February 15, 1923.

To all whom it may concern.

Be it known that I, CONRAD THURSTONE, citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Spring Suspension Systems for Vehicles, of which the follow ng is a specification.

This invention relates to vehicle spring suspension systems, and more particularly to spring suspension systems used on self propelled vehicles, such as passenger andv eight automobiles, as well as to chassis of aerial vehicles.

One of the principal objects of this invention is to provide a spring suspension of such resiliency as to eliminate the necessity of devise a spring suspension system which is more protected against mud and rain than are the systems of spring suspension now in provide a spring suspension system in which the loads and greater resiliency shocks are carried by a great number of easily renewable springs, thus insuring and a greater factor of safety against total breakdowns. Still another object is to provide a spring suspension system in which provisions are made to reduce the lateral swaying motions of the vehicle body, the rebounds and unspfung weight to a minimum, Another im-' port-ant object is to devise such a system of spring suspension which is practical and which can lee-manufactured at relatively low cost. Further advantages and features of the present invention will appear from the description anddrawings forming part of this application. I

In the drawings Fig. 1 is atop plan view of an automobile chassis built in accordance with my invention.

Fig. 2 is a longitudinal section taken along line 22 in Fig. 1.

Fig. 3 is a cross-sectional line 33, Fig- 1.

. Fig. 4: is a partial plan view showing the application of my invention to an automoile chassis of the chain-drive type. .Fig. 5 is a cross-sectional view taken along line'55 in Fig. 4.

Fig. 6 is a side elevation of a pneumatic shock regulator used in' connection with my View taken on Another object is to.

Serial No. 619,208.

Fig; 7 is a cross-sectional view taken substantially on line 77, Fig. 6. Fig. 8 is an enlarged view of an air valve used in my-pneumatie shock regulator.

Fig. 9 is a plan view of a resilient bag used in the shock regulator- Fig. '10 is a fractional view showing a modified construction of a resilient axle suspension.

Referring to Figs. 1, 2 and 3, the vehicle frame 1 is supported upon the wheel axles 2 and 3 by means of the bell-crank levers 4 and 5, rockably mounted \the transverse stationary rod 6 and the shorter stationary rods 7. The latter are supported at one end in the frame 1 and at the other end in the upwardly turned U- shaped support 74, mounted upon the transverse bottom plate 75. Rods 7 are placed in alignment but are spaced endwise to prorespectively upon 76 and. universal joint 77. These parts, as well as the transmission case 105 and the 1differential 106, are shown in dot and dash .ines.

The shorter, and substantially vertical arms 8 and 9 of the bell-crank-levers are made. of sufficient width to accommodate the attachment of the required number of coil springs 10, the other ends of which are suitably secured to cross bars 11 former ones being short and rigidly mounted between one side of the frame 1 and special plates 13, held in place by the rod 6 and a cross tie-rod 14. The cross bar 12 extends across the frame and acts-also as a tie-rod therefor, being securely held by means of the bolt nuts 15 screwed upon its threaded ends 16.

'drical casing 24, closed at the top and secured by means of flanges 25 upon the axlecasings 26 and 27, shown in the drawings as and 12; thebeing of. L-shaped cross-section. The outer ends of arms 17 and 18 are suspended from the springs 23 by the piston members 28.

' the radial are also used to strengthen both leaf spring.

and 7.

The upward movementsvof the axles are limited by the stops 91 secured to the frame and provided on their striking s de with pads 92 of any desired resilient and durable material, to absorb the shocks and the noise thereof. a i

In heavy duty automobile trucks,the front axle 2 is preferably strengthened against distortion by means of the radial braces-29, secured to the front axle casing 26 by means of bolts or rivets 31, whereas the inner end of said radial brace is pivotally secured by means of the bolt 32 to a substantially U-shaped member 33 which is rockable upon the transverse rod 6- Spacer rivets 34 and legs of the radial brace.

The .rear axle is similarly strengthened for heavy loads by the radial bracev30, the outer ends of which are secured to the rear axle casing 27 by the rivets 36. The closed inner end 37 of this radial brace is also pivotally connected to the U-shaped member 38 by means of a pin 39. Member 38 is rockabl mounted upon the inner ends of the rods Said inner end of the radial brace is moreover connected to the center of a transverse leaf spring 40 (the purpose of which is described hereafter) by means of at one end upon thea fiat .plate il, fastened angle iron member 42, secured to the brace, and at the other end to Rivets 43 and 4e are indicated as means for securing plate l1.

Springs 10 are furthermore assisted in carrying the loadsby transverse coil-springs 4E5 and-46 mounted respectively on rods 6 One end of said transverse springs is held stationary in any suitable manner, whereas the other end acts upon the short arms 8-and 9 m the same sense as springs 10.

Lateral rocking of the vehicle body and frame is" greatly attenuated by the transverse leaf-spring 40, the longer leaves of which are turned down to form the extensions 47 engaged bythe stationary rods 7 It will be not-ed that, on account of the spring 40 being connected at the center of brace 30, both ends of the former will be enabled to. follow the sidewise rock mg movements of the frame, while at the same time retarding and reducing their intensity. In the drawings is shown the application of but one'tiiansverse leaf-spring; but it will be readily understood that, if needed, a similar spring could be connected to the forwardi brace 29 and the transverse rod 6.

' springs,

By the action of the bell-crank-levers and when either one or more wheels strike an obstacle, their axle .is brought nearer the frame 1 and immediatdy thereafter the reaction of the springs would force the'frame and body suddenly upward, and

a prolonged up and down swaying thereof would result. To prevent, or reduce this,

passing suddenly the underside of said i each long arm of the bell-crank-levers is connected to a pneumatic shock regulator, the function of which is to permit the quick upward motion of the axles and dampen the rebound action' of the springs.

Thepreferred construction of the shock regulator is especially shown in Figs. 6 to is from belly 4:9 to belly 50, will find the I valve wide open, as shown in Fig. 8, whereas flow is reversed, the seat 58 and through the when the direction of valve-disc will close upon its the air will be forced to flow small holes, thus retarding the passage of the air from flow 1n the direction of the arrow correbelly 50 to belly L9. The air sponds to the upward movement of a wheel over an obstacle, while the reverse flow serves to regulate the rebound action of'the springs.

Each rubber bag is enclosed in a suitably shaped housing 61, open at the bottom and closed at'the top by a cover 62 held in place by screws 63. The housing is securely mounted on the frame 1 with screws 64 and is positioned in vertical alignment with the long arm of lever.

The bellies 4:9 and 50 of the rubber, bags are acted upon by the angularly disposed flat arms 65 and 66 respectively of a lever .67 centrally mounted within the housing hingedlysecurcd the connecting rod 70, the

lower end of which is also hingedly mounted bv means of a pm connection 71 to a clamping member 72 adjustably. securable upon the long arms 17 or 18 through the bolts 73. My system of spring suspension can also ,be a )plied to chain driven'vehicles. Such an appmation is illustrated in Figs. and It willbe noted therein that the required changes affect the driving mechanism exclusively. The rods 7 in Figs. 1 and 2 are replaced by the shafts 7 S and T9 driven by the differential gear shown in dot and dash lines. The inner ends of shafts 78 and 9 are mounted for rotation in a central bearmg support 81 resting upon the transin which are also its corresponding bell-crankverse plate 81, secured to the frame by means of rivets 82 and corner angles'83. Said shafts are supported outwardly -in bearings 84 mounted upon the side plates 85 depending from frame 1.

Power from the drive shaft 86 is transmitted to the rear axle through the Sprockets 87, mounted on shafts 7 8 and 79 and connectcd by means of the sprocket chain 88 to the sprocket wheels 89, secured in any desired manner to the rear wheels 90. The other parts i are similar to those used for shaft driven vehicles and have been identified by the same numerals.

In the modified construction shown in Fig. 10, the light-load spring 23 and correlated parts have been eliminated, thus reducing the cost of manufacture. In this modification the'long arm 93 of the bell-crank lever 94 is fastened suitably to the axle casing 95, such as by bolts 96 engaging holes 96 made somewhat larger to take care of the slight frelative movements between the bell-cranklever and the axle, due to the up and down increments of the latter. The short leverarm 97 is formed integrally with the long arm 93 thus producing a one-piece bellcrank-lever, having its fulcrum on rods 6 or 7. i

The free ends 98 of coils 10 pass through suitable apertures 99 in the short arm and are lengthened and partly threaded to enable the mounting thereon of the light-load springs 100 which are clamped between out side, cup-shaped, washers 101 and flanges sleeve-members 102. These sleeves act as guides for the s rings; their rear ends 103, which contact with the small arm 97, being preferably made spherical to facilitate the adjustment of the springs to the various positions which the bell-crank-lever may take. The tension of the springslO and 100 may be regulated, within limits, by the threaded nuts 104 screwed upon the free ends 98.

The operation of my spring Suspension system will be easily understood from the following explanation taken in connection with the preceding description: In the construction shown in Figs. 1 to 5, when the loaded vehicle is standing still, or running over a smooth road, the load is resiliently carried by the springs 23 which are'considerably weaker than springs 10. The latter may in fact be considered, for the time eing, as nonresilient connecting members. However, when the wheels of the vehicle, while running. suddenly strike an obstacle, the strain on the springs 23 is so much aug mented as tocompress them completely into a solid body and, then only, do the strong springs 10 come into play and absorb the excessive road shocks. The pneumatic shock regulators will operate under smooth and rough running conditions; but it is, especially in the latter case that their rebound regulating action will beof greatest effect.

If but one wheel strikes an obstacle, the shock on the wheel will cause considerable lateral swaying of the frame and body. This swaying is taken care of by the transverse leaf-spring 40, assisted also by the action of the pneumatic shock-regulators 48.

Similarly, when the modified construction shown in Fig. 10 is used, the normal loads at standstill, or smooth running, will be borne by the springs 100 and the heavy shocks by the strong sprlngs 10.

From the foregoing description it is obvious that this spring suspension system will function equally well in the chassis of an aerial vehicle, where it will accelerate the initial ascent and lessen the impact on landing. By the application of this spring system both to landing 1 heels and wing-wheels, the danger of breakage and first shock on alighting would be greatly reduced.

Detailed description and illustration of the application of this sprlng suspension system proper to the chassis of an aerial vehicle would be a duplication of some of the foregoing, and therefore mention of such application of this system is deemed sutlicient.

As will be understood, as suggested herein, there may be slight changes made in the construction and arrangement of details of my invention without departing from the field and scope of the appended claims, in this application in which the preferred forms only of myinvention are disclosed in connection with automobile chassis.

hat I claim is:

1. In a vehicle, the combinationof bellerank levers having long andshort arms; resilient means for normally holding said long arms in a substantially horizontal posi-. tion; axles supported-on the free ends of said long arms; transversely disposed resilient means for absorbing the lateral swaying movements of the superstructure of said vehicle, and fluid means for regulating the rocking movements of said bell-crank levers.

2. In a vehicle, the combination of bellcrank levers having long and short arms; resilient means-for normally holding said long arms in a substantially horizontal position; axles resiliently supported on the free ends of said long arms; transversely disposed unitary resilient means for absorbing the lateral swaying movements of the superstructure of said vehicle, and fluid means for regulating the rocking movements of said bell-crank levers.

3. In a vehicle, the combination of bell- 125 crank levers having long and short arms; resilient means for normally holding said long arms in a substantially horizontal posi- 'tion;'resilient means for supporting axles upon the free endof said long arms: said latter resilient means being Weaker'than said former resilient means; transversely disposed resilient means for absorbing the lateral swaying movements of the superstructure of said vehicle, and pneumatic means for regulating the rocking movements of said bell-crank levers. gt

4. In a vehicle, the combination of bellcrank levers having long and short arms:

resilient means for normally holding said long arms in a substantially horizontal position; resilient means for supporting axles upon the free end of said long arms; said latter resilient means being Weaker than said said bell-crank being so disposed as to enable the quick upformer resilient means; transversely disposed resilient means; for absorbing the lateral swaying movements of the superstructure of said vehicle; pneumatic means for regulating the rocking movements of levers; said pneumatic means ward rocking movements of said axles and retard the rebound action of the resilient means cooperating with said bell-crank levers.

V I In testimony whereof I afiix my signature.

CONRAD THURSTQNE. 

